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iSCSI Server Configuration In RHEL-6

iSCSI (Internet Small Computer System Interfac)iSCSI is Internet SCSI (Small Computer System Interface), an
Internet Protocol (IP)-based storage networking standard for linking data
storage facilities by carrying SCSI commands over IP networks. iSCSI is used to
facilitate data transfers over intranets and to manage storage over long
distances. iSCSI makes block devices available via the network. We can mount
block devices (disks) across an IP network to local system and then use them
like any other block device. iSCSI is a client-server protocol. The server-side
is referred to as the 'target,' while the client-side is referred to as the 'initiator.'
Both the target and initiator are uniquely identified by a string called the iSCSI
Qualified Name (iQN). Initiators come in two varieties: software and hardware.
A software initiator is just a driver that handles all requests and pairs the
network interfaces driver and the SCSI drivers together to make it work. Using
a software initiator any system with an Ethernet card can act as an iSCSI
initiator. A hardware initiator is an iSCSI HBA, which is basically just an
ethernet card with a SCSI ASIC onboard. Here we are configuring software
initiator in RHEL 6.

Step-2Configure network with ipaddress and make sure that clients
are reachable to the server. By default iSCSI will listen to the port 3260, we
have to add necessary rules in iptables to allow iSCSI. Ignore this step if
firewall is disabled.

#
iptables -I INPUT -p tcp -m tcp --dport 3260 -j ACCEPT#
service iptables save#
service iptables restartStep-3.(Allocate storage for the LUNs)The iSCSI target service is not dependent on a particular type
of exported LUN. The LUNs can be plain files, LVM volumes, or block devices.
There is however a performance overhead if using the LVM and/or file system
layers as compared to block devices. This example demonstrates the creation of a local partition /dec/sdb1 as iSCSI storage
LUN.